Typical automatic dishwashing products are formulated such that a 1% solution of the product has a pH of between 9 and 11.5. This is because in order to effectively clean the items found within the dishwasher and minimize the number of residues found in the machine filter, an automatic dishwashing product is formulated at high pH in order to effectively hydrate and swell soils, provide a pH range in which bleaches are effective (the hydroperoxide anion is a valuable bleaching species, either on its own or as a means to perhydrolyze a bleach activator such as TAED or charge a metal catalyst such as manganese methyltriazacyclononane, often known as Mn-TACN) and a pH in which triglyceride grease soils are effectively hydrolyzed.
At such high pHs, a significant quantity of insoluble calcium salts can be formed that lead to inorganic filming on items such as glasses, cutlery and plastic, particularly when the items are subjected to multi-cycles. This effect can be mitigated by use of strong soluble calcium builders such as MGDA and GLDA, although these represent an expensive solution to this problem.
The objective of the present invention is to provide an automatic dishwashing composition with provides good cleaning, shine and care.